So the problem is, when the installer is in the zimbra-core installating gives an installation failed error, the output:

Code:

You appear to be installing packages on a platform different
than the platform for which they were built.
This platform is CentOS5_64
Packages found: RHEL6_64
This may or may not work.
Using packages for a platform in which they were not designed for
may result in an installation that is NOT usable. Your support
options may be limited if you choose to continue.
Install anyway? [N] Y
The system will be modified. Continue? [N] Y
Removing /opt/zimbra
Removing zimbra crontab entry...done.
done.
Cleaning up zimbra init scripts...done.
Cleaning up /etc/ld.so.conf...done.
Cleaning up /etc/prelink.conf...done.
Cleaning up /etc/security/limits.conf...done.
Finished removing Zimbra Collaboration Server.
Installing packages
zimbra-core......zimbra-core-8.0.2_GA_5569.RHEL6_64-20121210115059.x86_64.rpm...FAILED
###ERROR###
zimbra-core-8.0.2_GA_5569.RHEL6_64-20121210115059.x86_64.rpm installation failed
Installation cancelled

I already make an uncle Google search and I just find some threads about issues when update from 7.0 to 7.2, I already search here in the forum and not found info, so if any one knows some about this in advance thank's.

So the problem is, when the installer is in the zimbra-core installating gives an installation failed error, the output:

I would have thought the problem was self-evident from the error messages you've received but if it's not:

Code:

You appear to be installing packages on a platform different
than the platform for which they were built.
This platform is CentOS5_64
Packages found: RHEL6_64
This may or may not work.
Using packages for a platform in which they were not designed for
may result in an installation that is NOT usable. Your support
options may be limited if you choose to continue.

On which operating system are you installing ZCS and which version did you download? Get the correct version and install that and you should have no problems.

I would have thought the problem was self-evident from the error messages you've received but if it's not:

Code:

You appear to be installing packages on a platform different
than the platform for which they were built.
This platform is CentOS5_64
Packages found: RHEL6_64
This may or may not work.
Using packages for a platform in which they were not designed for
may result in an installation that is NOT usable. Your support
options may be limited if you choose to continue.

On which operating system are you installing ZCS and which version did you download? Get the correct version and install that and you should have no problems.

Thank's Phoenix for your answer, how my thread and my post says the Operative System is a CentOS 5.9 with the latest patches, and the version of the zimbra installer is 8.0.2, how You know, and as far as I know, there's never been a release of a package build for CentOS, You can check this right here Open Source Edition Downloads: Enterprise Messaging and Collaboration Software by Zimbra, the installer says that I'm running the installer in a OS that's not build for, that's the reason why I'm using the --platform override flag. I installing ZCS since 6.x over CentOS and is the firs time I see this issue, if You need additional information about my system I will keep around here.

Thank's Phoenix for your answer, how my thread and my post says the Operative System is a CentOS 5.9 with the latest patches, and the version of the zimbra installer is 8.0.2, how You know, and as far as I know, there's never been a release of a package build for CentOS, You can check this right here Open Source Edition Downloads: Enterprise Messaging and Collaboration Software by Zimbra, the installer says that I'm running the installer in a OS that's not build for, that's the reason why I'm using the --platform override flag. I installing ZCS since 6.x over CentOS and is the firs time I see this issue, if You need additional information about my system I will keep around here.

Ignore this post, I read again the Phoenix post and my problem is because I try to install the Release version for RHEL6 on a CentOS 5 so is almost logical the reason of my "issues".